Decorative floor covering comprising polyethylene terephthalate film layer in surface layer and manufacturing method of the same

ABSTRACT

The present invention provides a decorative floor covering comprising a surface layer and a substrate layer underneath, wherein the surface layer comprises a polyethylene terephthalate film layer, and a method for preparing the same. Furthermore, the present invention provides a decorative floor covering comprising a surface layer and a substrate layer underneath, wherein a light weight back layer is further comprised under the substrate layer, and a method for preparing the same. A decorative floor covering of the present invention is a decorative floor covering which has superior surface heat resistance, printing sharpness and realism, and it can be installed conveniently since not only can non-foamed polyvinyl chloride resin be used as a substrate layer, but also the weight of a floor covering is light when a light weight back layer is comprised under the substrate layer.

CROSS REFERENCE TO RELATED APPLICATION

This application is based on Korean patent application Nos.10-1999-0024426 and 10-2000-0034772 filed on Jun. 26, 1999 and Jun. 23,2000 respectively, which are incorporated hereinto by reference.

BACKGROUND OF THE INVENTION

(a) Field of the Invention

The present invention relates to a decorative floor covering, moreparticularly to a decorative floor covering comprising a polyethyleneterephthalate film layer in a surface layer, and a manufacturing methodof the same.

(b) Description of the Related Art

As demands for convenience and health functions in home environmentsincrease in conjunction with recent income level improvements, the needfor light weight decorative floor coverings and various functionalproducts used in a common residence or commercial space tends to beincreasing.

A decorative floor covering which is installed in common residences anda semi-commercial spaces provides simple functionalities such asdurability, stain resistance and fashion characteristics.

Methods for printing decorative patterns in conventional decorativefloor coverings include directly printing patterns on a polyvinylchloride resin sheet, directly printing patterns on a substrate layercomprising glass fiber etc., and transferring printed patterns on paperor polyester film to a polyvinyl chloride resin sheet surface. However,there have been problems in that these methods do not satisfy humandesires for natural patterns without leaving artificial traces.Particularly, although effects of a pattern which is printed on paper orpolyester transfer paper is superior, there have been problems in thatrealism decreases since pattern changes occur after transfer.Furthermore, although a polyvinyl chloride resin layer is formed by toadding fillers to a polyvinyl chloride resin sheet layer to raise thetransferring effects since complete transfer does not occur due totransferring surface irregularities, the transferred patternsdeteriorate due to the fillers.

Secondly, conventional decorative floor coverings in which an olefinresin skin layer such as a transparent polyvinyl chloride resin,polyethylene, etc. is used on a printing layer so as to protect theprinting layer tend to generate microscopic air pockets duringprocessing, so a yellowing phenomenon occurs due to the heat changesduring processing. In addition, a certain thickness should be maintainedin order to provide durability during use, resulting in the problem thattransparency is further deteriorated due to the thickness.

Thirdly, polyvinyl chloride resin has problems of poor heat resistancein that the surface is easily damaged by a heat source of over 100° C.due to its low softening point of 80 to 100° C.

Although there have been cases that non-foaming polyvinyl chloride resinor other materials have been used as a skin layer to improve heatresistance, problems of heat resistance have not been fundamentallysolved.

Furthermore, a non-foaming polyvinyl chloride resin layer has been usedunder a conventional decorative floor covering as a balance layer, andthere have been installing problems since the product weight isincreased due to the resin layer.

FIG. 1 is a cross-sectional view of a conventional decorative floorcovering, wherein a substrate impregnated layer 1 is positioned in themiddle, a non-foaming chip layer 21 having a pastel tone and decorativepatterns, a durability provided polyvinyl chloride resin skin layer 22,and a durability and heat resistance provided surface treated layer 25are positioned in order on the substrate impregnated layer 1, and abalance layer 31 which maintains product balance is positioned under thesubstrate impregnated layer 1.

The above conventional decorative floor coverings are manufactured by amethod comprising the steps of heat pressing and gelling after fullyimpregnating glass fiber, pulp, etc. having large pores into a polyvinylchloride resin sol to make a substrate impregnated layer 1, formingpolyvinyl chloride resin chips on non-foamed chips 21 by applying heatafter coating calcium carbonate (CaCO₃) contained polyvinyl chlorideresin chips having 5 to 7 colors to a thickness of 1.0 to 1.5 mm on thesubstrate impregnated layer 1 using a rotary screen roll, laying up atransparent polyvinyl chloride resin sheet on the non-foamed chips 21 asa skin layer 22, laying up a calcium carbonate filled polyvinyl chlorideresin sheet under the substrate impregnated layer 1 as a balance layer31, and forming a surface treated layer 25 by curing after coatingurethane acryl resin, etc. on the skin layer 22.

The conventional decorative floor coverings having these structures haveproblems in that realism is decreased in the decorative patterns of thenon-foamed chip layer 21, transparency of the durability providingpolyvinyl chloride resin skin layer 22 is decreased, and its heatresistance is insufficient.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a decorative floorcovering having a superior heat resistant surface and a method formanufacturing the same, considering problems of the conventionaltechnologies.

It is another object of the present invention to provide a decorativefloor covering having superior surface printing sharpness and realism,and a method for manufacturing the same.

It is another object of the present invention to provide a light weightdecorative floor covering which can be installed conveniently sincenon-foamed polyvinyl chloride resin is used as a substrate layer, and amethod for manufacturing the same.

In order to accomplish the above objects, the present invention providesa decorative floor covering comprising a surface layer and a substratelayer, wherein the surface layer comprises a polyethylene terephthalatefilm layer.

Furthermore, the present invention provides a decorative floor coveringcomprising a surface layer and a substrate layer, wherein a light backlayer is further comprised underneath the substrate layer.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete appreciation of the invention, and many of the attendantadvantages thereof, will be readily apparent as the same becomes betterunderstood by reference to the following detailed description whenconsidered in conjunction with the accompanying drawings, wherein:

FIG. 1 is a cross-sectional view of a conventional decorative floorcovering;

FIG. 2 is a cross-sectional view of the decorative floor covering ofEXAMPLE 1;

FIG. 3 is a cross-sectional view of a decorative floor covering in whicha glass fiber scrim or a woven or non-woven glass fiberis interposed inthe middle of a polyvinyl chloride resin substrate layer of the presentinvention;

FIG. 4 is a cross-sectional view of the decorative floor covering ofEXAMPLE 2;

FIG. 5 is a cross-sectional view of the decorative floor covering ofEXAMPLE 3; and

FIG. 6 is a cross-sectional view of the decorative floor covering ofEXAMPLE 4.

DETAILED DESCRIPTION OF THE INVENTION

In the following detailed description, only the preferred embodiments ofthe invention have been shown and described, simply by way ofillustration of the best mode contemplated by the inventor(s) ofcarrying out the invention. As will be realized, the invention iscapable of modification in various obvious respects, all withoutdeparting from the invention. Accordingly, the description is to beregarded as illustrative in nature, and not restrictive.

The present invention is described in detail as following.

The present invention is a decorative floor covering downwardlycomprising a surface layer 20 with a polyethylene terephthalate filmhaving superior transparency, heat resistance, durability, and chemicalresistance, and a polyvinyl chloride substrate layer 10 having a highfiller content. That is, it is an aim that at the point when a hightemperature is applied to the surface of conventional polymer plasticfloor coverings, the high temperature is transferred so that not only docarbonization phenomena not occur, but the heat is transferred veryquickly. So, a UV coated polyethylene terephthalate film having superiorheat resistance is used in the surface layer 20, and polyvinyl chlorideresin having a high filler content is used as a substrate so as toswiftly transfer a high temperature applied to the floor coveringsurface so that the decorative floor covering surface is not carbonizedeven at a high temperature. Furthermore, patterns of a decorative floorcovering are vividly expressed using superior transparency andprintability of a polyethylene terephthalate film.

Therefore, printing sharpness and realism are high and heat resistanceis improved in a decorative floor covering of the present invention.

The present invention is described in detail with drawings as follows.

FIG. 2 is a cross-sectional view illustrating one embodiment of thepresent invention, wherein a polyvinyl chloride resin substrate layer 10is disposed in a decorative floor covering, and a surface layer 20 isdisposed on the substrate layer 10. The surface layer 20 can be furthersubdivided. That is, the surface layer 20 comprises a surface treatedlayer 25 on a polyethylene terephthalate film layer 24, and a polyvinylchloride resin intermediate layer 23 under that.

A method for manufacturing a decorative floor covering of FIG. 2basically comprises the steps of:

-   -   a) manufacturing a polyvinyl chloride resin substrate layer 10;    -   b) manufacturing a pressed sheet by laying up a polyvinyl        chloride resin intermediate layer 23 on the substrate layer 10,        applying pressure, and pressing;    -   c) manufacturing a half-finished sheet by laying up a        polyethylene terephthalate film layer 24 under which a certain        pattern is printed on the pressed sheet of step b), applying        pressure, and pressing; and    -   d) forming a surface treated layer 25 by UV curing after coating        a surface treated layer 25 composition on the half-finished        sheet of step c).

In the pressing of step b) and step c), the pressing objects arepreferably preheated to a temperature of 140 to 170° C. before layingup, and the applied pressure is preferably from 3 to 10 kgf/cm² duringpressing.

The polyvinyl chloride resin substrate layer 10 fulfils its function todissipate heat applied to the top of the surface layer 20, and it ismanufactured by adding a high amount of fillers. Usable fillers includeone or more inorganic fillers selected from the group consisting ofcalcium carbonate, talc, wollastonite, and silica, one or more metallicpowders selected from the group consisting of aluminum, copper, andiron, and a mixture thereof. In the fillers used, an inorganic filler ispreferably from 50 to 400 weight parts based on 100 weight parts ofpolyvinyl chloride resin, and a metallic powder is preferably from 5 to30 weight parts based on 100 weight parts of polyvinyl chloride resin.In order to improve processabilities of a calender, the consumed amountcan be increased 2 to 5 times more by processing after premixing ametallic powder, a resin, and a plasticizer than when a metallic powderalone is used.

A preferable method embodiment for manufacturing a polyvinyl chlorideresin substrate layer 10 is manufacturing a sheet by adding aplasticizer for reinforcing product flexibility, 30 to 50 weight partsof dioctyl phthalate, heat resistant stabilizers for providing heatresistant stabilities, 3 to 5 weight parts of a barium-zinc basedcompound and 3 to 5 weight parts of epoxy compound, a filler forproviding product hardness and heat resistant dispersibility, 50 to 400weight parts of calcium carbonate (CaCO₃), and 3 to 5 weight parts ofpigment for imparting surface colors, to 100 weight parts of polyvinylchloride resin, fully kneading at a rolling mill at 160 to 190° C., androlling to a thickness of 0.8 to 1.3 mm.

Preferably 50 to 400 weight parts of a calcium carbonate filler are usedbased on 100 weight parts of polyvinyl chloride resin since the higherthe content of calcium carbonate, not only does the heat conductibilityincrease, but also press marks caused by heavy objects such as furnitureused in everyday life are minimized due to an increased surfacehardness. However, when 400 or more weight parts of calcium carbonateare used based on 100 weight parts of polyvinyl chloride resin, thepolyvinyl chloride resin does not chemically bond with the calciumcarbonate, weakening the cohesion of the polyvinyl chloride resinresulting in a processibility decrease, even though it is profitable inthe aspect of manufacturing cost.

Furthermore, glass fiber scrim, or woven or nonwoven long glass fiber 11can be interposed in the middle of the polyvinyl chloride resinsubstrate layer 10 for dimensional stability, wherein the interpositionmethod is pressing and applying pressure of 3 to 10 kgf/cm² at anembossing roll under the state of latent heat of 100 to 150° C. afterrolling the first polyvinyl chloride resin sheet at a calender.Thereafter, the second polyvinyl chloride resin sheet is pressed under aglass scrim layer, or a woven or nonwoven glass fiber 11, thusinterposing it inside a polyvinyl chloride resin substrate layer 10, andthe second polyvinyl chloride resin sheet under which a separate lightback layer 30, usually a fiber layer 35, can be attached in advance.

A structure of a decorative floor covering of the present invention inwhich a glass fiber scrim or woven or nonwoven glass fiber 11 isinterposed in a polyvinyl chloride resin substrate layer 10 isillustrated in FIG. 3 and FIG. 4.

The polyvinyl chloride resin intermediate layer 23, which is used on apolyvinyl chloride resin substrate layer 10 so that color of a substratelayer 10 can be concealed in order to support printed pattern sharpnessand realism of an upper surface layer 20 has the additional function ofdissipating heat when heat is applied to the upper surface layer 20, andit also transfers heat to the polyvinyl chloride resin substrate layer10 positioned underneath.

For this, a 0.1 to 1 mm thick sheet is manufactured by rolling apolyvinyl chloride resin composition comprising 100 weight parts ofpolyvinyl chloride resin, 25 to 50 weight parts of dioctyl phthalate, 50to 150 weight parts of calcium carbonate, 3 to 5 weight parts oftitanium oxide, and 2 to 5 weight parts of heat stabilizer in acalender.

More particularly, after adding 25 to 50 weight parts of dioctylphthalate plasticizer for reinforcing product flexibility, 2 to 5 weightparts of barium-zinc (Ba—Zn) based stabilizer and 2 to 5 weight parts ofepoxy stabilizer heat resistant stabilizers for providing heat resistantstability, 50 to 150 weight parts of inorganic filler such as calciumcarbonate etc. for providing product hardness and heat resistantdispersibility, and 3 to 5 weight parts of titanium oxide (TiO₂) pigmentfor making the surface color white, to a main raw material of polyvinylchloride and sufficiently kneading at a rolling roll at 160 to 190° C.,a polyvinyl chloride resin intermediate layer 23 is manufactured byrolling to 0.1 to 1 mm, more preferably to a 0.1 to 0.2 mm thickness ina calender.

The polyethylene terephthalate film layer 24, under which highlyrealistic and vivid decorative patterns are printed by a printing methodsuch as gravure printing method, etc., is positioned on the polyvinylchloride resin intermediate layer 33.

It is preferable to use this polyethylene terephthalate film layer 24after coating a primer selected from the group consisting of polyvinylacetate based, polyurethane acrylate based, and ethylenevinyl acetatebased primers to a coating thickness of 0.1 to 10 μm for adhesion to anUV surface treated layer 25 positioned at the upper surface of the filmlayer and to a polyvinyl chloride resin intermediate layer 23 positionedunder the film layer.

Printing certain patterns on a polyethylene terephthalate film layer 24is possible before or after the primer treatment, and the polyethyleneterephthalate film layer is used during pressing by winding on a paperpipe, steel pipe, etc. after manufacturing. Furthermore, printing can bedone on the polyvinyl chloride resin intermediate layer 23 as opposed tothe polyethylene terephthalate film layer 24.

A thickness of a polyethylene terephthalate film layer 24 is preferablyfrom 10 to 100 μm, because when the polyethylene terephthalate film isthinner than 10 μm the printing surface is expanded by tension duringlaying-up, and when it is thicker than 100 μm product surface foldingoccurs when the product is folded since polyethylene terephthalate filmhas low flexibility when it is thicker than 100 μm.

The surface treated layer 25 which is used to provide stain resistanceor durability synergistic effectsis formed by coating an UV surfacetreated layer 25 composition on the polyethylene terephthalate filmlayer 24, and curing with ultraviolet rays, etc. A UV surface treatedlayer 25 composition is preferably selected from the group consisting ofurethane acrylate, silicone acrylate, and epoxy acrylate, and preferablyfurther comprising acryl based or urethane based beads having a particlesize of 5 to 20 μm, in order to maintain the heat resistant function. Itis cross linking cured with ultraviolet rays or electron beams: urethaneacryl resin is cured by ultraviolet ray irradiation depending oncomposition, and aqueous urethane resin can be cured with heat.

Ease of installation can be provided by additionally using a corkbalance layer 33 as a light back layer 30, or a wooden powder balancelayer 34, or a fabric layer 35 underneath the polyvinyl chloride resinsubstrate layer 10, thus reducing the weight of the decorative floorcovering while maintaining the same total thickness. The light backlayer 30 consisting of a cork balance layer 33, wooden powder balancelayer 34, or a fabric layer 35 can provide anti-insect effects, heatinsulating effects, a humidity controlling function, and impactabsorbing effects as well.

For this, the cork balance layer 33 is manufactured in a sheet which iscut to a thickness of 1.0 to 2.0 mm using a slicing machine after a corklayer of a natural tree is peeled off, and pulverized to a particle sizeof 5 to 10 meshes, put into a large cylinder together with adhesive, andbonded by applying pressure. A cork having preferably 2% or lessmoisture content is used since a higher moisture content causes highercontraction or expansion due to heat. A cork balance layer 33 can bemanufactured to a thickness of 3.0 to 4.0 mm so as to further improveperformance aspects such as sound insulation, impact absorption, etc.This cork balance layer 33 can improve the installation property ofproduct weight since its specific gravity is over 8 to 10 times lessthan a polyvinyl chloride resin sheet containing general inorganicmaterials.

Furthermore, the wooden powder balance layer 34 which maintains theproduct balance and provides anti-insect effects, heat insulatingeffects, a humidity controlling function, impact absorbing effects, etc.is manufactured in a sheet which is rolled to a thickness of 0.8 to 1.0mm using a two sets of pressure rolls after adding 100 to 150 weightparts of wooden powder having a particle size of 200 to 300 meshes, 3 to5 weight parts of heat resistant barium-zinc based compound as astabilizer, 1 to 3 weight parts of internal antiadditive stearic acid,30 to 50 weight parts of plasticizer dioctyl phthalate, and 3 to 5weight parts of other pigment to 100 weight parts of polyvinyl chlorideresin, and kneading it together, wherein the wooden powder is coatingtreated to prevent moisture absorption with 30 to 50 weight % ofsurfactant, based on the wooden powder weight. Polyethylene glycol,polybutyl glycol, polymethyl glycol, polymethyl propylene glycol, etc.can be used as a surfactant. Furthermore, surfactants having preferably2% or less moisture content are used since severe contraction orexpansion by heat can occur when moisture content is higher. The woodenpowder balance layer 34 can be manufactured to a thickness of 3,0 to 4.0mm to further improve functionality aspects such as sound insulation,impact absorption, etc. This wooden powder balance layer 34 can improvethe installation property of product weight since its specific gravityis over 8 to 10 times less than a polyvinyl chloride resin sheetcontaining general inorganic materials.

Furthermore, the fiber layer 35 which prevents product deformation bydimensional change and provides the product with lightness uses woven ornonwoven polyester, woven or nonwoven polypropylene, woven or nonwovenglass fiber, etc. This fabric layer 35 is used by fixing it with anadhesive after coating a plastisol such as polyvinyl chloride, etc.under the polyvinyl chloride resin substrate layer 10, andsimultaneously gelling the sol and pressing with the fiber layer 35, orpreparing it under the cork balance layer 33 or the wooden powderbalance layer 34. The woven thickness of the fiber layer 35 ispreferably from 10 s×10 s to 25 s×15 s, and the density is preferablyfrom 20×20 to 30×30 roll/inch.

This light back layer 30 is adhered under the polyvinyl chloride resinsubstrate layer 10 using an adhesive. The adhesive layer 32 ispreferably a sheet or impregnated sheet which is rolled to a thicknessof 0.03 to 0.2 mm by a 4 roll calender roll or an extruder at atemperature of 80 to 160° C. using urethane resin, acryl resin, vinylacetate, resin, etc. considering the melting point of each resin, and alight back layer 30 can be adhered by separately coating a plastisolsuch as polyvinyl chloride, etc. under a polyvinyl chloride resinsubstrate layer 10 and using this gelled sol. In case of using a rolledsheet or an impregnated sheet as an adhesive layer 32, a pressed productor half-finished product to be adhered is preheated, an adhesive layer32 is positioned under a substrate layer 10, laid up, and pressed with apressure of 3 to 10 kg/cm₂.

A decorative floor covering of the present invention is manufactured bythe various manufacturing methods depending on the application method ofthe light back layer 30. These manufacturing methods can be representedin the following various embodiments in addition to the above describedbasic manufacturing method.

One embodiment of a manufacturing method of a decorative floor coveringof the present invention comprises the steps of:

-   -   a) manufacturing the first polyvinyl chloride resin substrate        layer 10;    -   b) pressing by applying pressure in a embossing roll after        positioning a glass fiber scrim or a woven or unwoven glass        fiber 11 underneath the first substrate layer 10 under the        condition that a surface of the first polyvinyl chloride resin        substrate layer 10 of step a) maintains latent heat of 100 to        150° C.;    -   c) manufacturing the second polyvinyl chloride resin substrate        layer 10;    -   d) coating a plastisol underneath the second polyvinyl chloride        resin substrate layer 10, positioning a light back layer 30 of a        fiber layer 35, applying pressure, and pressing with a press        roll at a heating drum at 140 to 150° C.;    -   e) manufacturing a polyvinyl chloride resin intermediate layer        23;    -   f) manufacturing a pressed sheet by applying pressure at a press        after downwardly positioning a polyvinyl chloride resin        intermediate layer 23, the first polyvinyl chloride resin        substrate layer 10 under which glass fiber scrim, or woven or        unwoven glass fiber 11 is pressed, the second polyvinyl chloride        resin substrate layer 10 under which a light back layer 30 of a        fiber layer 35 is pressed, and preheating to a temperature of        140 to 170° C.;    -   g) manufacturing a half-finished sheet by applying pressure and        pressing at an embossing roll after preheating the pressed sheet        of step f) to a temperature of 140 to 170° C. and positioning a        polyethylene terephthalate film layer 24 on a polyvinyl chloride        resin intermediate layer 23; and    -   h) forming a surface treated layer 25 by UV (ultraviolet ray)        curing after coating a surface treated layer 25 composition on        the half-finished sheet of step g).

Another embodiment of a manufacturing method of a decorative floorcovering of the present invention comprises the steps of:

-   -   a) manufacturing a polyvinyl chloride resin substrate layer 10;    -   b) laying up a polyvinyl chloride resin intermediate layer 23 on        the preheated substrate layer 10 of step a), applying pressure,        and pressing;    -   c) manufacturing a half-finished sheet by laying up a        polyethylene terephthalate film layer 24 on the preheated        polyvinyl chloride resin intermediate layer 23 of step b),        applying pressure, and pressing;    -   d) laying up an adhesive layer 32 underneath the preheated        half-finished sheet of step c), applying pressure, and pressing;    -   e) laying up a light back layer 30 underneath the adhesive layer        32 of step d), applying pressure, and pressing; and    -   f) forming a surface treated layer 25 after coating a surface        treated layer 25 composition on the pressed polyethylene        terephthalate film layer 24 of step e), and curing.

In the manufacturing method, a method for laying up and pressing a lightback layer 30 can be selected from a method for laying up and pressing afabric layer 35 underneath a wooden powder balance layer 34 after layingup and pressing a cork balance layer 33 underneath an adhesive layer 32,or laying up and pressing a wooden powder balance layer 34 underneath anadhesive layer 32.

In the manufacturing methods, the preheating in each step is carried outat a temperature preferably from 140 to 170° C. considering the meltingpoint of polyvinyl chloride resin, and an applying pressure duringpressing after preheating is preferably from 3 to 10 kg/cm₂.

A surface treated layer 25, a polyethylene terephthalate film layer 24,a polyvinyl chloride resin intermediate layer 23, a substrate layer 10,and an adhesive layer 32 in a decorative floor covering of the presentinvention are manufactured in a thickness preferably from 1 to 1.5 mm.

The present invention is described further in detail through thefollowing EXAMPLES and COMPARATIVE EXAMPLES. However, the followingEXAMPLES are only for exemplifying the present invention, and thepresent invention is not limited to the following EXAMPLES.

EXAMPLES Example 1

(Manufacturing of a polyvinyl chloride resin substrate layer 10)

A polyvinyl chloride resin substrate layer 10 sheet having a thicknessof 0.75 mm was manufactured by kneading 100 weight parts of polyvinylchloride resin having a degree of polymerization of 1000, 42 weightparts of dioctyl phthalate, 250 weight parts of calcium carbonatepowder, and 2 weight parts of heat resistant stabilizer in a Banburymixer, and rolling the softened and molten compound with a calender at130 to 170° C.

(Manufacturing of a polyvinyl chloride resin intermediate layer 23)

A polyvinyl chloride resin intermediate layer 23 sheet having athickness of 0.1 mm was manufactured by kneading 100 weight parts ofpolyvinyl chloride resin having a degree of polymerization of 1000, 38weight parts of dioctyl phthalate, 90 weight parts of calcium carbonatepowder, 2.5 weight parts of heat resistant stabilizer, and 10 weightparts of titanium oxide in a Banbury mixer, and rolling the softened andmolten compound with a calender at 130 to 170° C.

(Pressing of a polyvinyl chloride resin intermediate layer 23)

After preheating the manufactured polyvinyl chloride resin substratelayer 10 sheet at a temperature of 150 to 170° C., a polyvinyl chlorideresin intermediate layer 23 was positioned on the preheated substratelayer 10, laid up, and pressed at a pressure of 3 to 6 kg/cm².

(Manufacturing of a polyethylene terephthalate film layer 24)

Certain patterns were imparted in the gravure printing method under apolyethylene terephthalate film (SG88 manufactured by SK Corporation)having a thickness of 50 μm on both sides of which an acryl andpolyester based primer is treated to an average thickness of 0.5 μm.

(Pressing of a polyethylene terephthalate film layer 24)

After preheating a sheet in which a polyvinyl chloride resinintermediate layer 23 was pressed on the manufactured polyvinyl chlorideresin substrate layer 10 sheet at a temperature of 150 to 170° C., thepolyethylene terephthalate film layer 24 under which certain patternswere imparted was positioned on the preheated sheet, laid up, andpressed at a pressure of 3 to 6 kg/cm².

(Heat resistant UV (ultraviolet rays) coating treatment)

A urethane acrylate based heat resistant UV treating agent in which aheat resistant stabilizer and acryl beads were added and contained wascoated on the polyethylene terephthalate film layer 24 pressed sheet toa coating thickness of 25 μm cured by an UV lamp in the non-oxygencuring method, thus forming a heat resistant UV coating layer 25 on theuppermost layer. This manufactured decorative floor covering isillustrated in FIG. 2.

Example 2

(Manufacturing of a polyvinyl chloride resin substrate layer 10)

The same polyvinyl chloride resin substrate layer 10 sheet as in theEXAMPLE 1 was manufactured.

(Attaching of woven cloth 30)

After coating a polyvinyl chloride sol (plastisol) under the polyvinylchloride resin substrate layer 10 sheet, a polyester woven cloth(thickness: 20 s×20 s, density: 25×25/inch) was positioned and pressedwith a press roll at a heating drum at 140 to 150° C.

(Pressing of glass fiber scrim 11)

One polyvinyl chloride resin substrate layer 10 sheet was additionallymanufactured by rolling a polyvinyl chloride substrate layer 10 sheetusing a calender in the same method as in the EXAMPLE 1, and pressed byapplying pressure while passing the sheet and glass fiber scrim (averageweight of 200 g/m²) which is positioned underneath the sheet through anembossing roll (pressure of 10 kgf/cm²) in the state of sheet formation,i.e., in the state that a latent sheet surface temperature of 100 to120° C. is maintained.

(Manufacturing of a polyvinyl chloride resin intermediate layer 23)

The same polyvinyl chloride resin intermediate layer 23 as in theEXAMPLE 1 was manufactured.

Each of a polyvinyl chloride intermediate layer 23, a polyvinyl chlorideresin substrate layer 10 sheet under which a glass fiber scrim 11 ispressed, and a polyvinyl chloride resin substrate layer 10 sheet underwhich polyester woven cloth is pressed were respectively preheated to atemperature of 140 to 170° C., downwardly positioned in order, laid up,and pressed by passing through an embossing roll at 160° C. (pressure of10 kgf/cm²).

(Manufacturing of a polyethylene terephthalate film layer 24)

The same polyethylene terephthalate film layer 24 as in the EXAMPLE 1was prepared.

(Pressing of a polyethylene terephthalate film layer 24)

After preheating the manufactured pressed sheet at a temperature of 150to 170° C., the polyethylene terephthalate film layer 24 under whichcertain patterns were imparted was positioned on the preheated sheet,laid up, and pressed at a pressure of 3 to 6 kgf/cm².

(Heat resistant UV coating treatment)

An urethane acrylate based heat resistant UV treating agent in which aheat resistant stabilizer and acryl beads were added and contained wascoated on the polyethylene terephthalate film layer 24 pressed sheet toa coating thickness of 25 μm, cured by an UV lamp in the non-oxygencuring method, thus forming a heat resistant UV coating layer 25 on theuppermost layer. The final product thickness was 1.8 mm. Thismanufactured decorative floor covering is illustrated in FIG. 4.

Example 3

(Manufacturing of a polyvinyl chloride resin substrate layer 10)

The same polyvinyl chloride resin substrate layer 10 as in the EXAMPLE 1was manufactured.

(Manufacturing of a polyvinyl chloride resin intermediate layer 23)

The same polyvinyl chloride resin intermediate layer 23 as in EXAMPLE 1was manufactured.

(Pressing of a polyvinyl chloride resin intermediate layer 23)

A polyvinyl chloride resin intermediate layer 23 sheet was pressed on asubstrate layer 10 in the same method as in EXAMPLE 1.

(Manufacturing of a polyethylene terephthalate film layer 24)

The same polyethylene terephthalate film layer 24 as in the EXAMPLE 1was manufactured.

(Pressing of a polyethylene terephthalate film layer 24)

A half-finished sheet was manufactured by pressing the polyethyleneterephthalate film layer 24 on a sheet in which a polyvinyl chlorideresin intermediate layer 23 was pressed on the polyvinyl chloride resinsubstrate layer 10 manufactured in the same method as in EXAMPLE 1.

(Manufacturing an adhesive layer 32)

A 0.1 mm thick adhesive layer 32 was manufactured by rollingvinylacetate resin using a 4 roll calender at 120° C.

(Pressing of an adhesive layer 32)

After preheating the polyethylene terephthalate film layer 24 pressedhalf-finished sheet at a temperature of 150 to 170° C. the adhesivelayer 32 was positioned under the preheated half-finished sheet, laidup, and pressed at a pressure of 3 to 6 kg/cm².

(Manufacturing of a cork balance layer 33)

A sheet which was cut to a thickness of 1 mm with a slicing machineafter a cork layer of a natural tree was peeled off, pulverized to aparticle size of 5 to 10 meshes, put into a large cylinder together with5 weight % of vinyl acetate adhesive per cork weight, and bonded byapplying pressure.

(Pressing of a cork balance layer 33)

The cork balance layer 33 was positioned underneath a half-finishedsheet under which the adhesive layer 32 is pressed, laid up and pressedat a pressure of 3 to 6 kg/cm².

(Heat resistant UV coating treatment)

An urethane acrylate based heat resistant UV treating agent in which aheat resistant stabilizer and acryl beads were added and contained wascoated on the pressed sheet to a coating thickness of 25 μm, cured by anUV lamp in the non-oxygen curing method, thus forming a heat resistantUV coating layer 25 on the uppermost layer. The final product thicknesswas 2.0 mm. This manufactured decorative floor covering is illustratedin FIG. 5.

Example 4

(Manufacturing of a polyvinyl chloride resin substrate layer 10)

The same polyvinyl chloride resin substrate layer 10 as in the EXAMPLE 1was manufactured.

(Manufacturing of a polyvinyl chloride resin intermediate layer 23)

The same polyvinyl chloride resin intermediate layer 23 as in EXAMPLE 1was manufactured.

(Pressing of a polyvinyl chloride resin intermediate layer 23)

A polyvinyl chloride resin intermediate layer 23 sheet was pressed on asubstrate layer 10 in the same method as in EXAMPLE 1.

(Manufacturing of a polyethylene terephthalate film layer 24)

The same polyethylene terephthalate film layer 24 as in the EXAMPLE 1was manufactured.

(Pressing of a polyethylene terephthalate film layer 24)

A half-finished sheet was manufactured by pressing the polyethyleneterephthalate film layer 24 on a sheet in which a polyvinyl chlorideresin intermediate layer 23 was pressed on the polyvinyl chloride resinsubstrate layer 10 manufactured in the same method as in EXAMPLE 1.

(Manufacturing an adhesive layer 32)

A 0.1 mm thick adhesive layer 32 was manufactured by rollingvinylacetate resin using a 4 roll calender at 120° C.

(Pressing of an adhesive layer 32)

After preheating the polyethylene terephthalate film layer 24 pressedhalf-finished sheet at a temperature of 150 to 170° C., the adhesivelayer 32 was positioned under the preheated half-finished sheet, laidup, and pressed at a pressure of 3 to 6 kg/cm².

(Manufacturing of a wooden powder balance layer 34)

A wooden powder balance layer 34 sheet was rolled to a thickness of 1 mmusing a two sets of pressure rolls at a temperature of 130 to 170° C.after kneading 100 weight parts of polyvinyl chloride resin, 150 weightparts of wooden powder having a particle size of 200 to 300 meshes, 5weight parts of heat resistant stabilizer barium-zinc based compound, 1weight part of internal antiadditive stearic acid, 30 weight parts ofplasticizer dioctyl phthalate, and 5 weight parts of pigment.

(Pressing of a cork balance layer 33)

The wooden powder balance layer 34 was positioned underneath ahalf-finished sheet under which the adhesive layer 32 was pressed, laidup, and pressed at a pressure of 3 to 6 kg/cm².

(Manufacturing of fiber layer 35)

A polyvinyl chloride sol (plastisol) coated polyester nonwoven(thickness: 20 s×20 s, density: 25×25/inch) was prepared.

(Pressing of a fiber layer 35)

The fiber layer 35 was positioned underneath a half-finished sheet underwhich the cork balance layer 33 was pressed, laid up, and pressed at apressure of 3 to 6 kg/cm².

(Heat resistant UV coating treatment)

An urethane acrylate based heat resistant UV treating agent in which aheat resistant stabilizer-and acryl beads were added and contained wascoated on the pressed sheet to a coating thickness of 25 μm, cured by anUV lamp in the non-oxygen curing method, thus forming a heat resistantUV coating layer 25 on the uppermost layer. The final product thicknesswas 2.0 mm. This manufactured decorative floor covering is illustratedin FIG. 6.

COMPARATIVE EXAMPLE 1 2.3 mm Thick Polyvinyl Chloride Resin DecorativeCushion Floor Covering

As a conventional 2.3 mm thick polyvinyl chloride resin decorativecushion floor covering, a Woodleum Plus product manufactured by LGChemical Ltd. downwardly comprising an UV coating layer, a transparentlayer, a printing layer, an upper foaming layer, a substrate layer, anunderneath foaming layer, and a sizing layer was prepared.

The Woodleum Plus product was manufactured by the following method.

(Manufacturing of a substrate layer 10)

A substrate layer was manufactured by gelling at a temperature of 150 to230° C. after depositing a sol made by mixing 100 weight parts ofpolyvinyl chloride resin having a degree of polymerization of 2000, 10to 100 weight parts of plasticizer, 1 to 20 weight parts of stabilizer,1 to 20 weight parts of pigment, 1 to 50 weight parts of calciumcarbonate, and other additives on a substrate such as glass fiber,vellum paper, or mineral material paper.

(Manufacturing of an upper foaming layer)

An upper foaming layer was manufactured by foaming at 170 to 250° C. for30 to 180 seconds after coating a sol made by mixing 100 weight parts ofpolyvinyl chloride resin having a degree of polymerization of 2000, 10to 120 weight parts of plasticizer, 1 to 20 weight parts of stabilizer,1 to 20 weight parts of pigment, 1 to 20 weight parts of foaming agent,and other additives to a thickness of 0.1 to 0.2 mm on the substratelayer.

(Manufacturing of a printing layer and a transparent layer)

A printing layer was formed by printing certain patterns on the upperfoaming layer using a gravure or offset ink, a rotary screen, and atransparent layer was manufactured by gelling at 170 to 230° C. for 30to 180 seconds after coating a sol made by mixing 100 weight parts ofpolyvinyl chloride resin having degree of polymerization of 2000, 10 to150 weight parts of plasticizer, 1 to 20 weight parts of stabilizer, andother additives to a thickness of 0.2 to 0.25 mm on the printing layer.

(Pressing of an underneath foaming layer and a sizing layer)

An underneath foaming layer was manufactured by foaming at 170 to 250° Cfor 30 to 180 seconds after coating a sol made by mixing 100 weightparts of polyvinyl chloride resin having a degree of polymerization of2000, 10 to 120 weight parts of plasticizer, 1 to 20 weight parts ofstabilizer, 1 to 20 weight parts of pigment, 1 to 20 weight parts offoaming agent, and other additives to a thickness of 0.1 to 0.2 mm onthe substrate layer, and a sizing layer was manufactured by gelling at170 to 230° C. for 30 to 180 seconds after coating a sol made by mixing100 weight parts of polyvinyl chloride resin having degree ofpolymerization of 2000, 10 to 120 weight parts of plasticizer, 1 to 20weight parts of pigment, 1 to 20 weight parts of stabilizer, 1 to 100weight parts of calcium carbonate, and other additives to a thickness of0.1 to 0.5 mm on the underneath foaming layer.

(Manufacturing an UV layer)

A UV layer was manufactured by UV curing unsaturated polyester resin,urethane acryl resin, epoxy acrylate resin, or polyester acryl resin onthe transparent layer.

COMPARATIVE EXAMPLE 2 A Decorative Floor Covering Comprising a 3.0 mmThick Polyvinyl Chloride Resin Layer

As a conventional decorative floor covering comprising a 3.0 mm thickpolyvinyl chloride resin layer, a Deco Tile manufactured by LG ChemicalLtd. downwardly comprising an UV layer, a transparent film layer, aprinting layer, an intermediate layer, a base layer, and a back layerwas prepared.

(Manufacturing of a transparent film layer)

A 0.2 to 0.3 mm thick transparent sheet was manufactured by mixing 100weight parts of polyvinyl chloride resin having a degree ofpolymerization of 800 to 1000, 10 to 40 weight parts of plasticizer, 1to 20 weight parts of stabilizer, and other additives, and sheeting inthe continuous calendaring method.

(Manufacturing an UV layer)

An UV layer was manufactured by UV curing unsaturated polyester resin,urethane acryl resin, epoxy acrylate resin, or polyester acryl resin onthe transparent layer.

(Structure of other layers)

Other underneath layers were manufactured by an ordinary method, i.e.,continuously calendaring non-foaming sheet layers, whereby each layerwas manufactured by heat pressing at a temperature of 130 to 160° C.

The product thickness was 3 mm, and the thickness of a surface skinlayer from an uppermost layer, i.e., an UV layer to a transparent filmlayer was 0.25 mm.

COMPARATIVE EXAMPLE 3 1.8 mm Thick Polyvinyl Chloride Resin Non FoamingDecorative Floor Covering

As a conventional 1.8 mm thick polyvinyl chloride resin non foamingdecorative floor covering, a Luckstrong manufactured by LG Chemical Ltd.downwardly comprising an UV layer, a transparent skin layer, a chiplayer, a substrate layer, a base sol layer, and a back layer wasprepared.

The Luckstrong product was manufactured by the following method.

(Manufacturing of a substrate layer)

A substrate layer was manufactured by gelling at a temperature of 150 to200° C. after depositing a sol made by mixing 100 weight parts ofpolyvinyl chloride resin having a degree of polymerization of 2000, 10to 100 weight parts of plasticizer, 1 to 20 weight parts of stabilizer,1 to 150 weight parts of calcium carbonate, and other additives on asubstrate such as glass fiber, vellum paper, or mineral material paper.

(Manufacturing of a base sol layer and a chip layer)

After manufacturing a base sol layer by coating a sol made by mixing 100weight parts of polyvinyl chloride resin having a degree ofpolymerization of 2000, 10 to 50 weight parts of plasticizer, 1 to 20weight parts of stabilizer, 1 to 20 weight parts of pigment, 1 to 50weight parts of calcium carbonate, and other additives to a thickness of0.1 to 0.2 mm on the substrate layer, a chip layer was manufactured byarranging on the base sol layer chips having a size of 8×9 mm which wereprepared after manufacturing a 0.8 to 1.2 mm thick transparent sheet bymixing 100 weight parts of polyvinyl chloride resin having a degree ofpolymerization of 800 to 1000, 10 to 40 weight parts of plasticizer, 1to 20 weight parts of stabilizer, 50 to 200 weight parts of calciumcarbonate, 1 to 5 weight parts of pigment, and other additives, andsheeting in the continuous calendaring method.

(Manufacturing of a transparent skin layer)

A transparent skin layer was manufactured by gelling at 170 to 230° C.after coating a sol made by mixing 100 weight parts of polyvinylchloride resin having a degree of polymerization of 1700 to 2000, 10 to50 weight parts of plasticizer, 1 to 5 weight parts of stabilizer, andother additives to a thickness of 0.1 to 0.2 mm on the chip layer.

(Manufacturing an UV layer)

An UV layer was manufactured by UV curing unsaturated polyester resin,urethane acryl resin, epoxy acrylate resin, or polyester acryl resin onthe transparent layer.

(Pressing of a back layer)

A back layer was manufactured by pressing with heat and pressure aftermanufacturing a 0.8 to 1.2 mm thick transparent sheet by mixing 100weight parts of polyvinyl chloride resin having a degree ofpolymerization of 800 to 1000, 10 to 40 weight parts of plasticizer, 1to 20 weight parts of stabilizer, 50 to 200 weight parts of calciumcarbonate, 1 to 5 weight parts of pigment, and other additives, andsheeting in the continuous calendaring method.

COMPARATIVE EXAMPLE 4 3.5 mm Thick Polyvinyl Chloride Resin DecorativeCushion Floor Covering

As a conventional 3.5 mm thick polyvinyl chloride resin decorativecushion floor covering, a Sharpeny product manufactured by LG ChemicalLtd. downwardly comprising an UV layer, a transparent layer, a printinglayer, an upper foaming layer, a substrate layer, and a mechanicalfoaming layer was prepared.

The Sharpeny product was manufactured by the following method.

(Manufacturing of a substrate layer)

A substrate layer was manufactured by gelling at a temperature of 150 to230° C. after depositing a sol made by mixing 100 weight parts ofpolyvinyl chloride resin having a degree of polymerization of 2000, 10to 100 weight parts of plasticizer, 1 to 20 weight parts of stabilizer,1 to 20 weight parts of pigment, 1 to 50 weight parts of calciumcarbonate, and other additives on a substrate such as glass fiber,vellum paper, or mineral material paper.

(Manufacturing of an upper foaming layer)

An upper foaming layer was manufactured by foaming at 170 to 250° C. for30 to 180 seconds after coating a sol made by mixing 100 weight parts ofpolyvinyl chloride resin having a degree of polymerization of 2000, 10to 120 weight parts of plasticizer, 1 to 20 weight parts of stabilizer,1 to 20 weight parts of pigment, 1 to 20 weight parts of foaming agent,and other additives to a thickness of 1.0 to 2.0 mm on the substratelayer.

(Manufacturing of a printing layer and a transparent layer)

A printing layer was formed by printing certain patterns on the upperfoaming layer using a gravure or offset ink, a rotary screen, and atransparent layer was manufactured by gelling at 170 to 230° C. for 30to 180 seconds after coating a sol made by mixing 100 weight parts ofpolyvinyl chloride resin having a degree of polymerization of 2000, 10to 150 weight parts of plasticizer, 1 to 20 weight parts of stabilizer,and other additives to a thickness of 0.2 to 0.25 mm on the printinglayer.

(Manufacturing of a mechanical foaming layer)

After manufacturing a sol by mixing 100 weight parts of polyvinylchloride resin having a degree of polymerization of 1100 to 2000, 60 to80 weight parts of plasticizer, 0 to 30 weight parts of calciumbicarbonate, 2 to 3 weight parts of stabilizer, and other additives, andputting the sol into a mechanical foaming layer, and manufacturing acream having a density of 0.3 to 0.7 g/cm² by high speed agitating at200 to 400 rpm while injecting air at 5 to 8 bar, a mechanical foaminglayer was manufactured by coating the cream to a thickness of 2 to 3 mmon the substrate layer, and gelling at 160 to 200° C.

(Manufacturing an UV layer)

An UV layer was manufactured by UV curing unsaturated polyester resin,urethane acryl resin, epoxy acrylate resin, or polyester acryl resin onthe transparent layer.

Example 5

(Transparency comparison)

In order to confirm vividness of printed patterns and transparency of apolyethylene terephthalate film layer 24 of the present invention, hazevalues of transparency of the polyethylene terephthalate film layer 24of the present invention and conventional polyvinyl chloride sheet layerwere measured more than 5 times by the method of ASTM D-1003, and theiraverage values are represented in the following Table 1.

A polyethylene terephthalate film (SG88 manufactured by SK ChemicalLtd.) was used in a polyethylene terephthalate film of the presentinvention, a comparison polyvinyl chloride sheet was manufactured aftermanufacturing a sol by mixing 100 weight parts of polyvinyl chlorideresin having a degree of polymerization of 2000, 10 to 50 weight partsof plasticizer, 1 to 20 weight parts of stabilizer, and other additives,coating the sol to a thickness of 0.2 mm, and gelling in an oven at 200°C., and the collected films of the sheet were used as samples.

TABLE 1 Polyethylene terephthalate Classification Polyvinyl chloridesheet film Haze value 35 to 45 3 to 5

Transparency results on sheets

It can be found from the results that a polyethylene terephthalate filmof the present invention has 10 or more times superior transparency thana polyvinyl chloride sheet. Therefore, since polyethylene terephthalatefilm has good transparency and uniform surface conditions, printingsharpness, realism, etc., and it can be raised in a decorative floorcovering in which patterns printed, this polyethylene terephthalate filmwas used in a surface layer 20.

Example 6

(Heat resistance test)

After installing a conventional 2.3 mm thick polyvinyl chloride resindecorative cushion floor covering, Woodleum Plus, of the COMPARATIVEEXAMPLE 1 and a 1.8 mm thick decorative floor covering of the EXAMPLE 2on a general cement floor surface, it was measured whether damage of theproduct surface was shown per a period of time in the conditions that alit cigarette and an unglazed earthenware bowl were put on each sample.

The results are represented in the following Table 2.

TABLE 2 Heat resistance results per each structures A decorative floorcovering of A decorative COMPARATIVE floor covering Test ClassificationEXAMPLE 1 EXAMPLE 2 conditions Lit When left Carbonization No damagesTested with cigarette laid paral- after 30 by 5 minutes cigarettes lelto a seconds having a product size of When a carbonized No damages 8 mmcigarette is (diameter) × crushed 83 mm out (length) an unglazed Damagedafter Satisfactory Tested by earthenware bowl 3 seconds until cooledleaving boil- ing unglazed earthenware bowl on a product

It can be found from the results of the Table 2 that decorative floorcoverings using a polyethylene terephthalate film 24 of the presentinvention and a polyvinyl chloride sheet substrate layer 10 containing ahigh content of a filler have superior heat resistance.

Example 7

(Durability(abrasion resistance) test)

An abrasion amount of a surface skin layer having a thickness of 0.25 mmin a decorative floor covering having a conventional polyvinyl chlorideresin layer, that is, a Deco Tile of COMPARATIVE EXAMPLE 2 was measuredand compared to an abrasion amount of a polyethylene terephthalate filmlayer 24 having a thickness of 0.05 mm in a decorative floor covering ofEXAMPLE 2 of the present invention, using a Taber abrasion test machinein accordance with KSF 2813 (the abrasion testing method of constructionmaterials and composing components) in order to confirm durability of adecorative floor covering of the present invention.

The results are represented in the following Table 3.

TABLE 3 Abrasion resistance tests for each structure Decorative floorcovering of COMPARATIVE Decorative floor covering Classification EXAMPLE2 of EXAMPLE 2 Abrasion amout (g) 0.61 0.047 0.1 mm thickness 0.2 0.1converted abrasion amount (g)

It could be found that a decorative floor covering of the presentinvention was improved in durability two or more times compared to adecorative floor covering having a conventional polyvinyl chloride resinlayer from the results shown in the above Table 3.

Example 8

(Weight comparison)

A weight per m² was 3.24 kg when a non-foaming decorative floor coveringhaving a thickness of 2.0 mm was manufactured in COMPARATIVE EXAMPLE 3,while a weight per m² was 2.15 kg when a decorative floor coveringhaving a thickness of 2.0 mm was manufactured in EXAMPLE 3 of thepresent invention, confirming that 33.6% of weight reduction wasrealized in a decorative floor covering of the present inventioncompared to a conventional non-foaming decorative floor covering.

Furthermore, insect repelling effects, heat insulating effects, ahumidity controlling function, impact absorbing effects, and soundblocking effects in addition to the weight reduction can be expectedfrom using a cork balance layer 33 in a back layer, and insect repellingeffects, heat insulating effects, a humidity controlling function, andimpact absorbing effects can be expected from using a wooden powderbalance layer 34 in a back layer.

Example 9

(Sound blocking test)

After installing a 2.3 mm thick conventional vinyl cushion decorativefloor covering of the COMPARATIVE EXAMPLE 1, a 1.8 mm thick conventionalnon-foaming vinyl cushion decorative floor covering of the COMPARATIVEEXAMPLE 3, and a 2.0 mm thick decorative floor covering of the EXAMPLE 3on a 150 mm thick standard concrete slab, the sound blocking performancefor a light floor covering impact was measured in accordance with KSF2810 (the measuring method of floor impact sound at the building site)in order to confirm sound blocking effects of a decorative floorcovering, and the measurement results are represented in the followingTable 4.

TABLE 4 Sound blocking performance results on each structures ImprovedSingle amount of evaluation sound L- L- index blocking Structure classindex (dB(A)) performance Standard concrete slab (150 mm) L-75 74 75Standard Standard concrete slab L-65 66.9 66.9 Δ8.1 (150 mm) + adecorative floor covering of COMPARATIVE EXAMPLE 1 (thickness 2.3 mm)Standard concrete slab L-65 66.9 66.9 Δ8.1 (150 mm) + a non-foamingdecorative floor covering of COMPARATIVE EXAMPLE 3 (thickness 1.8 mm)Standard concrete slab L-50 50.1 50.1 Δ24.9 (150 mm) + a decorativefloor covering of EXAMPLE 3 (thickness 2.0 mm)

In the above Table 4, L-class represents a class showing a soundblocking degree according to the Japanese Industrial Standards, L-indexrepresents showing a sound blocking degree according to the standardsprepared by Korea National Housing Corporation, and single evaluationindex represents a sound blocked sound pressure level.

It could be confirmed from the above Table 4 that a decorative floorcovering of the present invention had superior sound blocking effects.

Example 10

(Indentation test)

After applying a pressure with an indentation testing machine, anequipment of which the front end is a 6.3 mm hemispheric steel rodcapable of applying a 133 N (13.6 kgf) load, for one minute inaccordance with KSM 3506 (regulation on a vinyl floor sheet for abuilding molded of a main raw material of polyvinyl chloride resin) inorder to confirm impact absorbing effects of a decorative floor coveringof the present invention, a indentation depth was measured by a dialgauge.

Indentation depths of a 2.3 mm thick conventional vinyl cushiondecorative floor covering of the COMPARATIVE EXAMPLE 1, a 1.8 mm thickconventional polyvinyl chloride resin non-foaming decorative floorcovering of COMPARATIVE EXAMPLE 3, and a 2.0 mm thick decorative floorcovering of EXAMPLE 3 of the present invention were measured andrepresented in the following Table 5.

TABLE 5 Indentation results on each structures 2.3 mm thick 1.8 mm thickdecorative floor decorative floor 2.0 mm thick covering of covering ofdecorative floor COMPARATIVE COMPARATIVE covering of EXAMPLE 1 EXAMPLE 3EXAMPLE 3 Classification (foaming) (non-foaming) (non-foaming)Indentation depth 1.25 0.71 0.89 (mm)

It could be confirmed from the results of the above Table 5 that therewere 25.3% improved effects compared to a 1.8 mm conventional polyvinylchloride resin non-foaming decorative floor covering although cushioncharacteristics were somewhat weaker than a 2.3 mm thick conventionalfoaming polyvinyl chloride cushion decorative floor covering.

Example 11

Temperature differences according to time of a 3.5 mm thick conventionalvinyl cushion decorative floor covering of COMPARATIVE EXAMPLE 4 and a2.0 mm thick decorative floor covering of EXAMPLE 3 of the presentinvention were measured and represented in the following Table 6.

TABLE 6 Heat accumulating effects on each structures 3.5 mm thick vinylcushion 2.0 mm thick flooring of COMPAR- decorative floor ATIVE EXAMPLE4 covering of EXAMPLE 3 Temperature Temperature Temperature differenceTemperature difference Time lapsed (° C.) (° C.) (° C.) (° C.) Productinitial 54 — 49 — temperature 42 12 39 10 1 hour 35 19 31 18 2 hours 3123 27 22 3 hours 27 27 25 24 4 hours

It could be confirmed from heat accumulating effect results on eachstructure of the above Table 6 that a 2.0 mm thick decorative floorcovering of the present invention had 3° C. or more heat insulatingeffects than a 3.5 mm thick conventional vinyl cushion decorative floorcovering.

A decorative floor covering of the present invention is a decorativefloor covering which has superior surface heat resistance, printingsharpness and realism, and it can be installed conveniently since notonly can non-foamed polyvinyl chloride resin be used as a substratelayer, but also the weight of the floor covering is light when a lightweight back layer is comprised under the substrate layer.

While the present invention has been described in detail with referenceto the preferred embodiments, those skilled in the art will appreciatethat various modifications and substitutions can be made thereto withoutdeparting from the spirit and scope of the present invention as setforth in the appended claims.

1. A decorative floor covering comprising: (i) a surface treated layer;(ii) a polyethylene terephthalate film layer; (iii) a polyvinyl chlorideresin intermediate layer wherein the polyvinyl chloride resinintermediate layer is a sheet having a thickness of 0.1 to 0.2 mmmanufactured by pressure rolling in a calendar a polyvinyl chlorideresin composition comprising 100 parts of polyvinyl chloride resin, 25to 50 weight parts of dioctyl phthalate, 50 to 150 weight parts ofcalcium carbonate, 3 to 5 weight parts of titanium oxide, and 2 to 5weight parts of heat stabilizer; (iv) a polyvinyl chloride resinsubstrate layer wherein the polyvinyl chloride resin substrate layer isa non-foamed polyvinyl chloride sheet manufactured by kneading apolyvinyl chloride resin composition comprising 100 weight parts ofpolyvinyl chloride resin, a plasticizer of 30 to 50 weight parts ofdioctyl phthalate, heat resistant stabilizers of 3 to 5 weight parts ofbarium-zinc based compound and 3 to 5 weight parts of epoxy compound,and fillers of 200 to 400 weight parts of calcium carbonate and 3 to 5weight parts of pigment in a rolling mill having a temperature of 160 to190° C., and pressure rolling it to a thickness of 0.8 to 1.3 mm; (v) anadhesive layer; and (vi) a light back layer.
 2. A decorative floorcovering in accordance with claim 1, wherein the polyethyleneterephthalate film layer is a film in which a primer selected from thegroup consisting of polyvinyl acetate based, polyurethane acrylatebased, and ethylene vinyl acetate based primers is coated to a filmthickness of from 0.1 to 10 μm on at least a top and a bottom side ofthe polyethylene terephthalate film layer.
 3. A decorative floorcovering in accordance with claim 1, wherein a thickness of thepolyethylene terephthalate film layer is from 10 to 100 μm.
 4. Adecorative floor covering in accordance with claim 1, wherein thepolyvinyl chloride resin substrate layer is comprised of glass fiberscrim, or woven or nonwoven glass fiber.
 5. A decorative floor coveringin accordance with claim 1 further comprising a light back layer beneaththe substrate layer.
 6. A decorative floor covering in accordance withclaim 5, wherein the light back layer comprises one or more layersselected from the group consisting of a cork balance layer, a woodenpowder balance layer, and a fiber layer.
 7. A decorative floor coveringin accordance with claim 6, wherein the cork balance layer is a sheetwhich is cut to a thickness of 1.0 to 2.0 mm with a slicing machineafter a cork layer of a natural tree is peeled off, pulverized to aparticle size of 5 to 10 meshes, put into a large cylinder together withadhesive, and bonded by applying pressure.
 8. A decorative floorcovering in accordance with claim 6, wherein the wooden powder balancelayer is a sheet which is rolled to a thickness of 0.8 to 1.0 mm using atwo sets of pressure rolls after adding 100 to 150 weight parts ofwooden powder having a particle size of 200 to 300 meshes, 3 to 5 weightparts of heat resistant stabilizer barium-zinc based compound, 1 to 3weight parts of internal antiadditive stearic acid, 30 to 50 weightparts of plasticizer dioctyl phtalate, and 3 to 5 weight parts ofpigment to 100 weight parts of polyvinyl chloride resin, and kneadingall the components together.
 9. A decorative floor covering inaccordance with claim 6, wherein the fiber layer is selected from thegroup consisting of woven or unwoven polyester, woven or unwovenpolypropylene, and woven or unwoven glass fiber, the woven thicknessbeing from 10 s×10 s to 25 s×15 s, and the density being from 20×20 to30×30 roll/inch.
 10. A decorative floor covering in accordance withclaim 1, wherein the surface treated layer of i) is a layer in which asurface treated layer composition comprising a resin selected from thegroup consisting of urethane acrylate, silicone acrylate, and epoxyacrylate is coated on the polyethylene terephthalate film layer, andcured with ultraviolet rays.
 11. A decorative floor covering inaccordance with claim 10, wherein the surface treated layer compositionfurther comprises an acryl based or urethane based bead having aparticle size of 5 to 20 μm.
 12. A decorative floor covering inaccordance with claim 1, wherein the total thickness of the i) surfacetreated layer, ii) polyethylene terephthalate film layer, iii) polyvinylchloride resin intermediate layer, iv) polyvinyl chloride substratelayer, and v) adhesive layer is from 1 to 1.5 mm.
 13. A decorative floorcovering in accordance with claim 1, wherein the adhesive layer of v) isa sheet in which urethane resin, acrylic resin or vinyl acetate resin isrolled to a thickness of 0.03 to 0.2 mm using 4 calender rolls at atemperature of 80 to 160° C., an impregnated sheet, or a plastisolcoating gel.